Carton for sealing by immersion



Dec. 3, 1946. s. BERGSTEIN 2,412,031

' CARTON FOR SEALING BY IMMERSION I F iled June 5, 1944 Samuel Bsnsga sthe like.

growth in recent years in the use of dlpping proc- Patented Dec. 3, 1946CARTON FOR SEALING BY IMMERSiON Samuel Bergstein,

Robert Morris Bergstein and Bergstein, trustees Cincinnati. Ohio,assignor to Frank David Application June 5, 1944, Serial No. 538,764

7 Claims. (01. 229-37) My invention relates to cartons designed to beproofed or sealed by immersing them in proofing agents. Such cartons areused for the packaging of milk, dairy products, frozen foods, and Therehas been a marked commercial esses for paperboard containers in thepackaging industry, employing a variety of fluid sealing mediumsincluding molten paraflin wax, wax and rubber mixtures, and. othersealing and proofing substances, to all of which my present inventionpertains. The cartons are provided on one end at least with closureflaps, which are folded over and adhesively secured. In some instances,the carton is provided with similar flaps at both ends and is filled andclosed; after which the entire carton is dipped in a bath of theproofing and sealing substance. In other instances, as in milk bottles,the carton is erected, closed at one end as described, and then passedthrough a bath of the proofing and sealing substance. Afterward, it isfilled, and then closed at the top by suitable closure means.

Both types of procedure and both types of carton present essentially thesame problem. each, at one or both ends, there is a closure formed byadhesively secured flaps lying in faceto-face relationship, with certainof the flaps presenting free or cut surfaces along'opposite side edgesof the closure. It is at these places that the greatest weakness in suchpackages is encountered. A slight imperfection in the coating elsewhere,as on a wall surface, or rupture or abrasion of the sealing medium on awall surface due to handling and shipping, does not necessarily weakenor rapidly destroy the effectiveness of the package itself. But theslightest imperfection or rupture of the coating along the free edges ofthe flaps at the end of a container starts leakage and loss ofefiectiveness almost immediately.

The principal object of my invention is the provision of means forovercoming this weakness and providing along the edges of the closurenot only a tight and dependable seal, but a seal oi such strength andresistance as to minimize damage in handling and shipping. It is myobject to accomplish this in a simple. and inexpensive manner.

These and other objects of my invention, which will be set forthhereinafter or will be apparent to one skilled in the art upon readingthese speciflcations, I accomplish by that certain construction andarrangement of parts, of which I shall now describe an exemplaryembodiment. Re!- erence is made to the accompanying drawing wherein:

Figure 1 is a partial plan view of a paperboard blank for a cartonembodying my invention.

' Figure 2 is a partial perspective view showing a stage in theformation of an end closure.

Figure 3' is a partial perspective view showing a later stage thereof. F

Figure 4 is a partial sectional view taken across the carton end closureafter immersion in the sealing snbstance.

I have'discovered that by providing a seal-end carton blank wherein theedges of an underlying sealing flap are recessed, I provide a structurewhich, when sealed, is characterized by a crevice along opposite edgesof the closure, whereby when such a, carton is dipped or immersed in thesealing medium, an excess or surplus oi the medium is retained in thecrevice.

When a so-called seal-end" carton is closed and adhesively secured, anintermediate flap lies above a pair of shorter'flaps and is covered byan outer flap. The intermediate .;'and outer flaps present cut edges atopposite sldesfof the closure, which are coterminous.

taining the flaps in their closed positions is not relied upon to effecta seal. When the carton is dipped, there may be formed a very thin skinor coating, overlying the cut edges of the board and the bent edges ofthe underlying flaps, which will make the structure initially liquidtight. The slightest rupture of this thin skin, however, destroys thesealed character of the container. There is little or no penetration ofthe sealing medium between the layers oi. board at the side edges of theclosure, and such penetration as there is cannot usually be relied upon.

However, if the edges of the intermediate flap are cut away 'orrecessed, there is presented, be-

tween the outer flap and the inner flaps, a recess having a width atleast as great as the thickness of a layer of board. The sealing mediumcollects in this recess directly bridging the gap between the outer flapand the inner flap, uniting them together in sealed relationship. Thethickness of the sealing medium/in this recess is sufllcient to give theseal strength and resistance to handling and scufllng so that theabrasions normally expected duringuse cannot destroy the seal. The sealhas none of the characteristics of a thin skin, but rather possesses thecharacteristics of a solid plug.

It is not, however, preferred'to recess or cut back the edges of theintermediate flap throughout the entire length of these edges. Thiswould The adhesive used in re- Referring to Figure 1,.I have shown aflat, out and creased paperboard carton blank comprising main bodypanels -I, 2, 3 and l and a glue flap 5 articulated together bylongitudinal score lines in the usual fashion. Closureflaps arearticulated by a common score line .to the ends of the body walls. Apair of closure flaps. 6 and 1, are short flaps, articulated to oppositewalls I and 3. An intermediate flap 8 is articulated to the body wall 2,while an outer flap 9 is articulated to the body wall 4. The flap 9 isof full dimensions to -extend entirely across the end of the carton. Theflap 8 is similarly dimensioned in general;

but its side edges are recessed, as shown at l and ll, not, however, forthe full length of these side edges. Adjacent the articulation of flap 8to wall 2 there are full width portions 12 and I3 of minor extent, andsimilar full width portions l4 and i occur adjacent the outer end of theflap.

The blank shown in Figure 1 is not complete and has been shown with oneclosure only. The

other end of thebody may be provided with an -flap between the extremeends thereof, leaving these extreme ends of full width.

exactly similar closure, where the carton is to be filledand closed andthen dipped bodily in the sealing bath. Where the carton is to be closedon one end only and then dipped, the other end may be provided with anydesired type of closure appropriate to the uses to which the carton isto be put. The size and cross-sectional shape of the carton form nolimitation upon my invention nor does the number of enclosing body wallspossessed by the carton, since it will be clear to one skilled in theart upon reading these specifications how the teachings hereof may beapplied to cartons of other polygonal cross-section.

The paperboard blank of Figure 1 is tubed in the ordinary way on theordinary carton tubing devices by being bent on a pair of intermediatescore lines, glue or other suitable adhesive being applied to themeeting surfaces of wall I and glue flap 5, and these being adheredtogether, as will be readily understood. The glue flap 5 may be adheredeither inside or outside the wall I. The blank may initially be made ofproofed board if desired; but this is not necessary for most purposes inview of the immersion treatment to which it will be subjected. The tubedblank is shipped'in the flap or collapsed form to the purpressure onboth sides of the closure to insure A proper setting of the adhesive,and aconformity ofthe flaps which is as complete as possible.

The carton, having been closed on one end as described, may then bebodily immersed in a bath of proofing and sealing substance. Or, if thecarton is of a type having the illustrated closure at each end, it maythen be inverted-filled with the desired contents, and similarlyclosed-'and 'adl0 hesively secured on the opposite. end, after which .itwill bedipped in a bath of proofing substance. While I have mentioneddipping, itwill be understood that this is the normal procedure; butthat other modes of applying the p'rooflng and sealing substance may beemployed without departing 1 from the spirit of my invention, such forexample,

as painting, spraying, or otherwise applying the coating agent or, inthe instance of cartons made of proofed boards, immersion of theendsthereof as distinguished from complete submergence in a bath. v Y.

Figure 4 is a semi-diagrammatic cross-sectiona1 view of the cartonshowing the closureand the] effect of dipping it into a bath ofproofingsubstance, or otherwise applying th substance as described. The flaps 6and I lie in a single plane surmounted by the intermediate flap 8 andthe outerflap 9, all of these flaps lying parallel and in face-to-facerelationship; but it will be seen that the edges of the intermediateflap 8 are spaced inwardly of the correspondingedges' of the overlyingflap 9 and the upper ends of the body walls of the carton, leavingrecesses. The

chaser.

The user squares up the tubular body of the blank and effects a closure.The firststage of this closure is illustrated in Figure 2 where theshort flaps 6 and I have first been folded in.- Glue orother adhesivemay be applied to flaps 6 and 1 if desired, and preferably will be soapplied.

A next stage is shown in Figure 3 where the in termediate flap 8 hasbeen folded over upon and preferably adhered to the short flaps 6 and 1.

Finally, the outer flap 9 will be folded over upon the intermediate flap8 with the interposition of adhesive between their meeting surfaces. Theclosure may be effected in any way desired; and

there are machines'available for the purpose formation of the externalcoating iii of proofing substance results in the introduction of thesubstance into the recesses, as shown in Figure 4 at H and i8. It willbenoted that the recesses are large enough so that capillarity or the lackof it is not controlling as to whether or'not they are filled. Hence, asdistinguished from the forma:

tion of a comparatively thin skinof sealing s stance over superposed andcoterminous out edges, of the board at the opposite sides of theclosure, with uncertain penetration of the sealing substance between theboard layers,'in my carton a heavy deposit of sealing substance at I1and! fills a definite recess in the structure anddirectly joins theouter flap 9 with the ends of the body I walls and immediately adjacentportions of the short flaps 6 and 1.. These masses of sealing substanceare quite strong; and the bond, and: consequently the seal, is notliable to destruction under ordinary handling strains.

Yet, the formation of my seal is a matter of] negligible expense. Itrequires only a slight mod: ification of the ordinary die by which thecarton blanks are cut and scored and a very slight addi- 1 tionalquantity of sealing substance in' th recesses, as at H and I8. Thephysical operations of closure and immersion are not altered as such, vi

and may be performed either by hand or on standard and availableequipment.

Modifications maybe made in my invention without departing from thespirit of it. Having thus described my invention in an exemplary embodiment, what I claim as new and desire to secure by Letters'Patent is:

1. A carton blank having enclosingbody walls I in articulation and endclosure flaps articulated to said body walls, said end closure flapsadapted to be folded in sequence to form a plural layered-j closure inwhich the flaps lie in Iace-to-fac'e en gagement and adhesive union, oneof said flaps, being an outer flap dimensioned to covertlie enif; v tireend cross-section of said body; another of said closure flaps being anintermediate flap sim-' ilarly dimensioned to cover the entire endcrosssection of said carton body, excepting that edge portions thereofwhere exposed in the closure are slightly recessed so as to extendinwardly of the corresponding edges of the outer flap to form recessesin said closure adapted to be filled with sealing substance.

2. The structure claimed in claim 1, wherein the recessed edges of saidintermediate. flap have at the ends one or more of said edge portions ofsubstantially full dimension so as to be coterminous with adjacentportions of the outer flap at corners of the closed carton body.

3. A blank for a paperboard carton scalable by immersion or the like,said blank comprising a body portion having four walls and a glue flapin articulation and an end closure comprising closing flaps, an oppositepair of said flaps being short enough in length to lie in the same planeacross an end of the carton formed from said blank, another flap,adapted to overlie said first mentioned flaps, being dimensioned tocover the entire cross section of the end of said carton excepting thatits' side edges are slightly recessed, and a fourth flap adapted tooverlie the last mentioned flap and dimensioned to cover the entirecross section of the end of said carton.

4. The structure claimed in claim 3, wherein the recessing of the edgesof the third mentioned flap is confined to intermediate portionsthereof, end portions of said edges being of full width.

5. The structure. claimed in claim 3, wherein the recessing of the edgesof the third mentioned flap is confined to intermediate portionsthereof, end portions of said edges being of full width, said cartonbody having at its opposite end a similar series of closure flaps.

6. A sealed carton comprising enclosing body walls in articulation andan end closure comprising flaps articulated to said body walls andadhered in face-to-face engagement, intermediate and outer ones of saidflaps dimensioned to cover the end of said carton, said intermediateflap having edge portions thereof recessed inwardly of correspondingedges of the outer flap, and a coating of sealing substance on saidcarton covering at least opposite edge portions of said closure andenteringsaid recesses whereby to seal edge portions of said outer flapdirectly to inner flaps past the recessed edges of said intermediateflap.

7. A sealed carton comprising enclosing body walls in articulation andan end closure comprising flaps articulated to said body walls andadhered in face-to-face engagement, intermediate and outer ones of saidflaps dimensioned to cover the end or said carton, said intermediateflap having edge portions thereof recessed inwardly of correspondingedges of the Outer flap, and a coating of sealing substance on saidcarton covering at least opposite edge portions of said closure andentering said recesses whereby to seal edge por-i tions of said outerflap directly to inner flaps past the recessed edges of saidintermediate flap, the said recessed edges of said intermediate flaphav- 7 ing portions at their corners of full width.

SAMUEL BERGSTE'IN.

